Historical clue formulations

• "Ain't that the truth!" — 2021-11-28
• Decidedly — 2021-06-13
• Verily — 2015-05-16
• "I agree!" — 2013-08-04
• "Absolutely!" — 2011-08-23
• To be sure — 2010-05-20
• Truly — 2009-10-19
• "Definitely!" — 2009-01-25
• "For sure!" — 2008-07-29
• "Really!" — 2005-05-19
• "You're so right!" — 2004-07-27
• Truly — 2003-11-24
• "You don't say!" — 2000-02-20
• "Without a doubt!" — 1995-03-10